strnlen

STRNLEN(3)                 Linux Programmer's Manual                STRNLEN(3)

NAME
       strnlen - determine the length of a fixed-size string

SYNOPSIS
       #include <string.h>

       size_t strnlen(const char *s, size_t maxlen);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       strnlen():
           Since glibc 2.10:
               _POSIX_C_SOURCE >= 200809L
           Before glibc 2.10:
               _GNU_SOURCE

DESCRIPTION
       The  strnlen()  function  returns  the  number  of  bytes in the string
       pointed to by s, excluding the terminating null  byte  ('\0'),  but  at
       most  maxlen.   In doing this, strnlen() looks only at the first maxlen
       characters in the string pointed to by s and never beyond s+maxlen.

RETURN VALUE
       The strnlen() function returns strlen(s), if that is less than  maxlen,
       or maxlen if there is no null terminating ('\0') among the first maxlen
       characters pointed to by s.

ATTRIBUTES
       For an  explanation  of  the  terms  used  in  this  section,  see  at-
       tributes(7).

       +----------+---------------+---------+
       |Interface | Attribute     | Value   |
       +----------+---------------+---------+
       |strnlen() | Thread safety | MT-Safe |
       +----------+---------------+---------+
CONFORMING TO
       POSIX.1-2008.

SEE ALSO
       strlen(3)

COLOPHON
       This  page  is  part of release 5.05 of the Linux man-pages project.  A
       description of the project, information about reporting bugs,  and  the
       latest     version     of     this    page,    can    be    found    at
       https://www.kernel.org/doc/man-pages/.

GNU                               2019-03-06                        STRNLEN(3)